|Publication number||US4563180 A|
|Application number||US 06/626,269|
|Publication date||Jan 7, 1986|
|Filing date||Jun 29, 1984|
|Priority date||Jun 29, 1984|
|Publication number||06626269, 626269, US 4563180 A, US 4563180A, US-A-4563180, US4563180 A, US4563180A|
|Inventors||James E. Jervis, Dennis A. Caponigro|
|Original Assignee||Raychem Corporation|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (20), Referenced by (47), Classifications (6), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to the field of catheters and, more particularly, relates to those catheters utilized for injecting fluids into a mammalian body.
Present-day catheters generally have a main body section in which the outside and inside diameters remain the same along the whole length of this section. These catheters may have a tip portion wherein the outside and inside diameters taper at the distal end. Illustrative are Cope, U.S. Pat. No. 4,405,314 (drainage catheter); Birtwell, U.S. Pat. No. 3,094,124 (arterial catheter); and Levy, U.S. Pat. No. 701,587 (catheter). In French Patent No. 2,119,261 there are shown configurations in which the inside and outside diameters vary along the length of the catheter.
Some catheters and other medical devices have a relatively small portion at the distal end in which the inside diameter diverges. Illustrative are Bazell et al., U.S. Pat. No. 3,890,976 (catheter tip assembly); Calabrese, U.S. Pat. No. 4,335,718 (needle cannula); Sheridan, U.S. Pat. No. 3,400,7814 (nasal cannula); Fresevins German, No. 05 2811 278 (cannula); and Poitras, U.S. Pat. No. 2,638,897 (flared exit phlebotomy needle). The outside diameters of these devices at the distal end may diverge, taper, or remain constant.
In Flamm, U.S. Pat. No. 2,734,665, there is a fluid device having a nozzle wherein the inside diameter varies over the length of the nozzle from a minimum at the proximal end to a maximum at the distal end. The outside diameter may taper toward the distal end. This nozzle is relatively short when compared to the length of a catheter. There is no indication that greater flow rate can be obtained with this configuration.
When injecting fluids into a mammalian body, e.g., a human body, it is often desirable to inject the fluids as rapidly as possible. However, due to the constraints imposed by trauma or the size of the vessels, the catheters used for injecting the fluids can only be of limited diameter. Flow rate is also limited by the strength of the catheter material since the wall thickness can only be so thin, dependent of course on the material, before the catheter bursts. No attempt has been made to alter the inside diameter along the length of the catheter to increase the flow rate. Accordingly, the flow rate possible for injecting fluids is necessarily limited with present-day catheters. It thus becomes desirable to optimize the design of the catheter so as to increase the flow rate.
It does not appear that any of the above prior art suggests a catheter for injecting fluids having an inside diameter which varies over the length of the catheter from a minimum at the proximal end to a maximum at the distal end. Nor does any of the prior art suggest varying the catheter configuration so as to increase the flow rate.
Accordingly, it is an object of this invention to optimize the design of the catheter for injecting fluids.
It is another object of the invention to vary the catheter configuration so as to increase the flow rate possible.
It is a further object of the invention to have a catheter that will increase the flow rate when injecting fluids but will not increase the amount of vascular trauma.
These and other objects of the invention will become apparent from reference to the following description considered in conjunction with the accompanying figures.
According to the invention there is disclosed a catheter for injecting fluids into a mammalian body. The catheter has an inside diameter, a proximal end for attachment to a fluid source, and a distal end for inserting into the body. The inside diameter of the catheter varies over its length from a minimum at the proximal end to a maximum at the distal end.
It has been found that such a design reflects an optimization of catheter design which results in an increase in flow rate over the prior art catheters.
FIG. 1 is a perspective view of a catheter according to the invention.
FIG. 2 is a sectional view of the catheter of FIG. 1 in the direction of arrows II--II.
FIG. 3 is a sectional view similar to FIG. 2 of a second embodiment of a catheter according to the invention.
Referring to the Figures in more detail and particularly referring to FIG. 1, there is disclosed a catheter 2 for injecting fluids into a mammalian body, for example a human body. The catheter has an inside diameter generally indicated by 4, a proximal end 6 for attachment to a fluid source (not shown), and a distal end 8 for insertion into the body (also not shown). The inside diameter of the catheter varies over its length from a minimum at the proximal end to a maximum at the distal end.
Now referring to FIG. 2, the cross section of the catheter of FIG. 1 is shown. It can be clearly seen in FIG. 2 that the inside diameter of the catheter varies over its length 10 from a minimum 12 at the proximal end 6 of the catheter to a maximum 14 at the distal end 8 of the catheter.
It can also be seen from FIGS. 1 and 2 that the catheter has a wall thickness which also varies over its length. The wall thickness varies from a maximum 16 at the proximal end of the catheter to a minimum 18 at the distal end of the catheter. In one preferred embodiment of the catheter, as shown in FIG. 2 the catheter would have a constant outside diameter 20 over substantially the entire length of the catheter.
Referring now to FIG. 3 there is shown a second embodiment of the catheter. The catheter 22 in FIG. 3 is the same as the catheter 2 of FIG. 2 except now the catheter 22 has an outside diameter which varies over its length from a maximum 24 at the proximal end 6 of the catheter to a minimum 26 at the distal end 8 of the catheter. In other respects the catheter 22 is the same as that shown in FIGS. 1 and 2, which includes the feature that the inside diameter of the catheter varies over its length from a minimum at the proximal end to a maximum at the distal end.
It is, of course, anticipated that the varying of the inside diameter of the catheter shown in FIGS. 1 to 3 can take many shapes. That is, it is not necessary that the transition from the minimum inside diameter to the maximum inside diameter occur gradually and uniformly. However, it is particularly preferred that the inside diameter tapers toward the proximal end of the catheter.
Similarly, at least with respect to the FIG. 3 embodiment, while the outside diameter of the catheter can vary over its length, it is preferred that the outside diameter vary by tapering toward the distal end.
In either of the embodiments of the catheter, it has been found that when the distal inside diameter 14 of the catheter is about 1.4 times the proximal inside diameter 12 of the catheter, certain advantageous effects of the invention will follow.
All the materials of construction commonly utilized in catheters are suitable for use with the catheter according to the invention. For purposes of illustration, and not of restricting the scope of the invention, some of these common catheter materials are polyurethane, polyethylene, polyamide, polytetrafluoroethylene, and silicone.
The instant invention is all the more significant as it runs contrary to current practice. This is true for two important reasons. The first reason is that a catheter having a varying internal diameter is difficult to manufacture. Therefore, one wishing to alter the design of the catheter would tend to avoid varying the internal diameter of the catheter and instead, choose a design that was easier to manufacture. The second reason is that when catheters are pressure-tested during manufacture they are simply clamped at one end and pressure is applied until the catheter bursts. According to this method of testing, which is inconsistent with actual use, the catheter will almost certainly fail at the thinnest wall thickness. Therefore the wall thicknesses of all catheters tend to be uniform.
Apparently it has not been recognized in the field of catheter design that further downstream from the entry of the fluid source, the pressure drastically decreases so that the thickness of the wall does not have to be as great. The following explanation may be instructive. The hydraulic forces involved in a tubular member can be approximated by the following equation:
R=radius of tube
σ=stress on the wall
t=thickness of tube
If the pressure decreases downstream from the entry of the fluid source, there must also be a corresponding drop in stress on the wall of the tube. Accordingly the thickness of the wall of the tube can be decreased downstream from the entry. In other words, the thickness of the wall of any tube under pressure must be at a maximum at the entry point of the pressure and at a minimum at the discharge end of the tube.
It has been found that the most beneficial results from varying the wall thickness occur when the inside diameter is varied from a minimum at the proximal end (entry of fluid source) to a maximum at the distal end (discharge of fluid).
A standard catheter was compared with a catheter according to the invention. The standard catheter had a constant inside diameter and outside diameter. The catheter according to the invention had a constant outside diameter and a varying inside diameter. The test results are as follows:
______________________________________ Standard Catheter of Catheter the Invention______________________________________PROXIMAL ENDInside Diameter, inches 0.055 0.055Outside Diameter, inches 0.102 0.095DISTAL ENDInside Diameter, inches 0.055 0.073Outside Diameter, inches 0.102 0.095FLOW RATE, ml/min 625.0 850.0______________________________________
The catheter according to the invention starts with an outside diameter smaller than the prior art catheter but ends up with an inside diameter greater than the prior art catheter. From the above test results, it can be seen that with the catheter according to the invention there is a substantially greater flow rate than with that of the prior art catheter.
Two conclusions can be drawn from these test results. The first is that for a given flow rate requirement, a smaller outside diameter catheter may be used; hence, vascular trauma is reduced. The second is that for a given outside diameter, a greater flow rate may be achieved, other factors such as material of construction being equal.
It will be obvious to those skilled in the art having regard to this disclosure that other modifications of this inventon beyond those embodiments specifically described here may be made without departing from the spirit of the invention. Accordingly, such modifications are considered to be within the scope of the invention as limited solely by the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US315023 *||Dec 30, 1884||Apr 7, 1885||Rubber tube for syringes|
|US701587 *||Feb 9, 1901||Jun 3, 1902||Alexander Levy||Applicator.|
|US1388172 *||Mar 18, 1920||Aug 23, 1921||Craddock Simon M||Veterinary surgical appliance|
|US2638897 *||Jan 18, 1951||May 19, 1953||Poitras Edward J||Flared exit phlebotomy needle|
|US2734665 *||Nov 1, 1951||Feb 14, 1956||Device for discharging liquids from|
|US3094124 *||Jun 30, 1960||Jun 18, 1963||Davol Rubber Co||Arterial catheter|
|US3227161 *||Mar 4, 1963||Jan 4, 1966||De Lorenzo Joseph P||Syringe|
|US3386438 *||Jul 7, 1965||Jun 4, 1968||Roehr Products Company Inc||Tapered needle|
|US3400714 *||May 3, 1965||Sep 10, 1968||Brunswick Corp||Nasal cannula|
|US3485234 *||Apr 13, 1966||Dec 23, 1969||Cordis Corp||Tubular products and method of making same|
|US3890976 *||Jan 21, 1974||Jun 24, 1975||Medical Products Corp||Catheter tip assembly|
|US4239042 *||Apr 5, 1979||Dec 16, 1980||Dow Corning K.K.||Catheter placement system|
|US4282876 *||Dec 28, 1979||Aug 11, 1981||Flynn Vincent J||Radiopaque polyurethane resin compositions|
|US4335718 *||Oct 2, 1980||Jun 22, 1982||Becton, Dickinson And Company||Needle cannula|
|US4385635 *||May 15, 1981||May 31, 1983||Ruiz Oscar F||Angiographic catheter with soft tip end|
|US4405314 *||Apr 19, 1982||Sep 20, 1983||Cook Incorporated||Apparatus and method for catheterization permitting use of a smaller gage needle|
|DE844642C *||Oct 31, 1950||Jul 24, 1952||August Loewenguth||Scheidenspuelvorrichtung|
|DE2427777A1 *||Jun 8, 1974||Feb 6, 1975||Henry Bridgman||Saugkuerette|
|DE2811278A1 *||Mar 15, 1978||Sep 27, 1979||Fresenius Chem Pharm Ind||Plastics-coated metal cannula for inserting into blood vessels - has bare tip, and constriction to render coating coplanar with metal tube for smooth insertion|
|FR2119261A5 *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5601603 *||Jun 9, 1994||Feb 11, 1997||White Spot Ag||Use of and process for the introduction of fibrin sealant into a puncture channel|
|US5836912 *||Oct 21, 1996||Nov 17, 1998||Schneider (Usa) Inc.||Catheter having nonlinear flow portion|
|US5846246 *||Feb 1, 1996||Dec 8, 1998||Cordis Corporation||Dual-balloon rapid-exchange stent delivery catheter with guidewire channel|
|US5851203 *||Jul 14, 1997||Dec 22, 1998||Cordis Corporation||Neuro-microcatheter|
|US6022341 *||Oct 3, 1997||Feb 8, 2000||Medtronic, Inc.||Catheter with multiple internal diameters|
|US6280423||Feb 23, 1999||Aug 28, 2001||Scimed Life Systems, Inc.||High flow rate dialysis catheters and related methods|
|US6361528||Apr 5, 1999||Mar 26, 2002||Acist Medical Systems, Inc.||Dynamically compliant catheter|
|US6595966||May 16, 2001||Jul 22, 2003||Scimed Life Systems, Inc.||High flow rate dialysis catheters and related methods|
|US6817995 *||Apr 20, 2000||Nov 16, 2004||Isotron ,Inc.||Reinforced catheter connector and system|
|US7410602||Apr 22, 2003||Aug 12, 2008||Namic/Va, Inc.||High flow rate dialysis catheters and related methods|
|US7931619||Apr 26, 2011||C. R. Bard, Inc.||Power injection catheters|
|US8323227||Dec 4, 2012||C. R. Bard, Inc.||Tip configurations for a multi-lumen catheter|
|US8328760||Jan 11, 2010||Dec 11, 2012||Angiodynamics, Inc.||Occlusion resistant catheter|
|US8337451||Dec 25, 2012||Angio Dynamics, Inc.||Recirculation minimizing catheter|
|US8403911||Mar 26, 2013||Becton, Dickinson And Company||Systems and methods for improving catheter hole array efficiency|
|US8480654||May 21, 2010||Jul 9, 2013||Cook Medical Technologies Llc||Catheter with expandable flow area|
|US8496629||Aug 10, 2010||Jul 30, 2013||Becton, Dickinson And Company||Catheter hole having a flow breaking feature|
|US8540663||Jul 2, 2008||Sep 24, 2013||Navilyst Medical, Inc.||High flow rate dialysis catheters and related methods|
|US8721826 *||Nov 19, 2010||May 13, 2014||Applied Medical Resources Corporation||Steerable kink-resistant sheath|
|US8894607||Nov 28, 2012||Nov 25, 2014||C. R. Bard, Inc.||Tip configurations for multi-lumen catheter|
|US8920404||Dec 16, 2011||Dec 30, 2014||C. R. Bard, Inc.||Reduction of recirculation in catheters|
|US8974411 *||May 21, 2008||Mar 10, 2015||Becton, Dickinson And Company||Conical diffuser tip|
|US9050435||Mar 22, 2011||Jun 9, 2015||Angiodynamics, Inc.||High flow catheters|
|US9056182||Aug 23, 2011||Jun 16, 2015||Becton, Dickinson And Company||Catheter having a pressure activated splittable feature|
|US20030204179 *||Apr 22, 2003||Oct 30, 2003||Davey Christopher T.||High flow rate dialysis catheters and related methods|
|US20040243103 *||May 25, 2004||Dec 2, 2004||Eric King||High pressure catheter and methods for manufacturing the same|
|US20050113739 *||Nov 21, 2003||May 26, 2005||Matthias Stiene||Device and method for extracting body fluid|
|US20060004325 *||Jul 2, 2004||Jan 5, 2006||Bret Hamatake||Tip configurations for a multi-lumen catheter|
|US20060149214 *||Dec 29, 2005||Jul 6, 2006||C. R. Bard, Inc.||Power injection catheters and method of injecting|
|US20070293349 *||Aug 21, 2007||Dec 20, 2007||Taylor Made Golf Company, Inc.||Golf club head having a composite face insert|
|US20090012481 *||Jul 2, 2008||Jan 8, 2009||Davey Christopher T||High Flow Rate Dialysis Catheters and Related Methods|
|US20090287186 *||Apr 21, 2009||Nov 19, 2009||Becton, Dickinson And Company||Systems and methods for improving catheter hole array efficiency|
|US20090292272 *||May 21, 2008||Nov 26, 2009||Becton, Dickinson And Company||Conical diffuser tip|
|US20100256546 *||Apr 3, 2009||Oct 7, 2010||Davis Scott A||Polycarbonate Polyurethane Venous Access Devices Having Enhanced Strength|
|US20100324503 *||Aug 10, 2010||Dec 23, 2010||Becton, Dickinson And Company||Catheter hole having a flow breaking feature|
|US20110066105 *||Nov 19, 2010||Mar 17, 2011||Applied Medical Resources Corporation||Steerable kink-resistant sheath|
|US20110071500 *||Mar 24, 2011||Navilyst Medical, Inc.||Branched catheter tip|
|US20110130745 *||Jun 2, 2011||Becton, Dickinson And Company||Catheter hole having an inclined trailing edge|
|US20110172642 *||Jul 14, 2011||Navilyst Medical||Occlusion Resistant Catheter|
|US20130338640 *||Aug 21, 2013||Dec 19, 2013||Angiodynamics, Inc.||High Flow Rate Dialysis Catheters and Related Methods|
|EP0419024A1 *||Aug 6, 1990||Mar 27, 1991||Theodore Chester Neward||Manipulable vacuum extractor for children|
|EP0643979A1 *||Aug 22, 1994||Mar 22, 1995||Cordis Europa N.V.||Microcatheter|
|EP0729766A1 *||Mar 3, 1995||Sep 4, 1996||Cordis Europa N.V.||Microcatheter|
|EP2627370A1 *||Mar 8, 2011||Aug 21, 2013||Medtronic, Inc||Cannular device and method of manufacture|
|WO1999017830A1||Jun 1, 1998||Apr 15, 1999||Medtronic, Inc.||Catheter with multiple internal diameters|
|WO1999042156A1 *||Feb 23, 1999||Aug 26, 1999||Boston Scientific Limited||High flow rate dialysis catheters and related methods|
|WO2014184238A1 *||May 14, 2014||Nov 20, 2014||Acandis Gmbh & Co. Kg||Medical catheter for hypothermic treatment, treatment system with such a catheter, and production method|
|Cooperative Classification||A61M25/0023, A61M25/0054|
|European Classification||A61M25/00R1, A61M25/00S3|
|Jun 29, 1984||AS||Assignment|
Owner name: RAYCHEM CORPORATION, 300 CONSTITUTION DRIVE, MENLO
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:JERVIS, JAMES E.;CAPONIGRO, DENNIS A.;REEL/FRAME:004281/0780
Effective date: 19840629
|Jul 6, 1989||FPAY||Fee payment|
Year of fee payment: 4
|Jun 21, 1993||FPAY||Fee payment|
Year of fee payment: 8
|Nov 18, 1996||AS||Assignment|
Owner name: MEDTRONIC, INC., MINNESOTA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:RAYCHEM CORPORATION;REEL/FRAME:008907/0388
Effective date: 19961004
|Jun 26, 1997||FPAY||Fee payment|
Year of fee payment: 12